In a system and method, the emitted beams of multiple diode bar array assemblies are combined to achieve an increase in the resulting power density in the combined output beam, while addressing the need for heat distribution in each of the individual assemblies. The present invention enables the combination of output planes of illumination, to form a single, merged beam of area A.sub.g having intensity I.sub.M.about.M*I.sub.stack and brightness B.sub.M.about.M*B.sub.stack, where I.sub.stack and B.sub.stack refer respectively to the intensity and brightness of the output plane of illumination of a single stacked array, and where I.sub.M and B.sub.M refer respectively to the intensity and brightness of the combined output plane of illumination of M stacked arrays. In this manner, the present invention is useful in applications where there is a need for high-intensity, high-brightness light energy.